Friction Definition and 998 Threads

  1. B

    Non-conservative work energy theorem and potential energy

    Here is problem I quickly made up: Suppose there is a ramp with a height of 6 meters and length of 12 meters. A block of 5 kg is pushed up to the top of the ramp with a constant velocity. The force of friction is 15 N. Here's the confusion: By using the non-conservative force work energy...
  2. robindymer

    B How does vibration affect the Higgs field interaction?

    I have been thinking about the Higgs field and how things interacts with it. I thought about why photons for example does not interact with it while quarks does. It could be because of the size and if when a particle is a certain size it will interact with the Higgs bosons and then slow down and...
  3. BenGuise

    How to calculate the rotational friction of square axle

    How would I calculate the frictional torque of rotating an axle with a square cross section? The axles that I’m using to drive a gear box are rectangular instead of cylindrical like normal axles, so I’m trying to figure out how much more a motor has to work to turn a square axle than it does to...
  4. J

    Work done on a shopping cart by friction when being pushed

    Homework Statement A grocery cart with mass of 19.3 kg is pushed at constant speed along an aisle by a shopper who exerts a force of 13.1 N on the cart at an angle of 18.3 from the horizontal. The aisle is 15.1 m long. The coefficient of friction is 0.0658. Find the work done on the cart by...
  5. J

    Coefficient of kinetic friction?

    Homework Statement A 2.79-kg block is placed on a rough surface inclined at 28.1°. The block is launched at a speed of 3.87 m/s up the incline, and comes to rest after sliding 0.969 m up the incline. Find the coefficient of kinetic friction between the block and the incline. Homework...
  6. F

    Harmonic Oscillator with Friction

    Homework Statement I don’t have a specific problem to solve, and I’m not sure I would be able to correctly find one, but I need to know how to solve a harmonic Oscilator problem with Friction. I believe I should be starting with F = -kx -Ff, and that I will be given some information about the...
  7. APphysicsSenior

    Acceleration of object with friction: Homework help

    A 50 kg box rests on the floor. The coefficients of static and kinetic friction are 0.70 and 0.50, respectively. a.) What is the minimum force required to start the box sliding from rest? b.) After the box starts sliding, the person continues to maintain that force. What is the...
  8. APphysicsSenior

    How to find coefficient of friction *Without* mass?

    A car traveling at 97 km/h can stop in 48 m on a level road a.) Determine the acceleration of the car b.) Determine the coefficient of friction between the tires and the road Homework Equations : Vf^2=Vo^2 +2aΔx μ=Ff/mg[/B] 3. I have part A, I got -7.53 m/s^2, but I can't seem to...
  9. V

    A Mystery of Einstein's Relativity Solved with Classical Physics

    https://curiosity.com/topics/a-mystery-of-einsteins-relativity-has-been-explained-using-classical-physics-curiosity?utm_source=androidapp If anybody understands what the author is trying to say, kindly elaborate. I haven't read the paper
  10. A

    How is the minimum work needed to push a car up an inclined plane calculated?

    Homework Statement What is the minimum work needed to push a 1000-kg car 300 m up a 17.5 degree incline? A. Ignore friction B. Assume the coefficient of friction is 0.25 Homework Equations W = F*d Net force = ma The Attempt at a Solution At first I did: Work = F*300*cos17.6 but I later...
  11. S

    Seal friction needed for pneumatic/hydraulic piston

    Hello, I have a project that requires me to calculate break force friction of a piston seal on the cylinder wall. I have a double acting cylinder at very low pressure, 3.5" diameter bore, one side of the piston is air, the other side is water. What seal type, seal compression, lubrication and...
  12. L

    Help finding obscure coefficient of friction

    Homework Statement I have a homework assignment that requires me to use the coefficient of static and kinetic friction for rubber on wood. I cannot locate this value anywhere so far. Homework Equations None. The Attempt at a Solution I have searched and searched and I cannot find the...
  13. A

    Finding work and the Change in Thermal Energy

    Homework Statement Kerry is pulling a 156-kg sled along a snowy, horizontal path with a 620-N force directed at an angle of 29.0° above the ground. He pulls the sled over a distance of 26.0 m, and the coefficient of kinetic friction between the sled and the ground is 0.0622. I need to find the...
  14. L

    Why is the Work Done by Friction on a Ramp Uncertain?

    The question that puzzled me during lecture! : A block is pushed so that it moves distance L up a ramp (incline angle q ) at constant speed. If there is friction, the magnitude of the work done on the block by friction…(ramp is up and leftwards) A. is mgsinqL. B. is less...
  15. A

    Calculating Work and Change in Thermal Energy

    Homework Statement In the question, a person is pulling a 156 kg sled up a hill. A 620 N force is used to pull the sled up the hill that has an angle of 29° with the horizontal. The sled is pulled a distance of 26 m, and the kinetic friction coefficient is 0.0622. The system has been defined as...
  16. A

    Static and kinetic friction help?

    I found a problem and I'm having one question, it goes like this: A box of 5 kg is being dragged across the floor with a horizontal force of 40 N. If it starts at rest and it begins to accelerate at 3 m/s2 (constant acceleration), find: A) The coefficient of kinetic friction B) Supposing that...
  17. A

    Speed of an object sliding down

    Homework Statement An object of mass m=2 kg slides down on a track from a height of h = 10 m. The track is frictionless except the horizontal range between the points A and B. The friction force is constant between A and B. What is the speed of the object at point B if the magnitude of the...
  18. N

    Basic Forces and Motion Problem (friction)

    1. Homework Statement You have two masses moving across a frictionless surface, yet there is friction between the two masses. Mass 2 is on top of Mass 1 A force is applied to m1 which causes It to accelerate at 6 m/s2 and the friction between the two masses causes m2 to accelerate at 4 m/s2...
  19. C

    Friction on an Inclined Plane: Solving for Acceleration and Forces

    Homework Statement There is a mass on incline surface that is acted by foces. μ=0.8 m=2 kg θ=30° g=10 m/s^2 ##F_N##= normal force ##F_F##= friction force ##Fg_x## = horizontal gravitational component ##Fg_y## = vertical gravitational component Homework Equations ##F_N=mg~cosθ##...
  20. T

    Deriving motion equations for two blocks on a rough table

    Two small blocks, each of mass m, are connected by a string of constant length 4h and negligible mass. Block A is placed on a very rough tabletop as shown below, and block B hangs over the edge of the table. The tabletop is a distance 2h above the floor. Block A is then released from rest at a...
  21. M

    Kinetic Friction Between Block and Surface (HW Check)

    Homework Statement A 10 g bullet is fired at 200 m/s into a 1 kg block after which they slide together 2 m on a horizontal surface. Determine the coefficient of kinetic friction between the block and surface. Homework Equations ##M_AV_{Ai} + M_BV_{Bi} = 0## ##WNC = ΔE## The Attempt at a...
  22. Oannes

    Finding Minimum Force Needed to Hold Object In Place

    Homework Statement A woman holds a book by placing it between her hands such that she presses at right angles to the front and back covers. The book has a mass of m = 0.75kg and the coefficient of static friction between her hand and the book is μs = 0.59. What is the minimum force she must...
  23. N

    Coefficient of friction in regards to a clamp force

    Does coefficient of friction change in regard to clamp force applied to parts? If you imagine a bench vice, clamping a plate with a weight attached. Can the clamp force required be calculated to hold a specific weight? I'm asking because I have an excavator mounted hammer EMV outside. It...
  24. H

    How Is Friction Force Calculated in Physics Problems?

    Homework Statement Box Mass = 64.7 kg T1 = 22.5° T2 = 54.1° F = 2327.9 N μdynamic = 0.19 μstatic = 0.37 What is the force of friction acting on the box? Homework Equations FF= mu x FN The Attempt at a Solution 64.7 x 9.81 = 634.707 0.19 x 634.707 = 120.69 Computer is telling...
  25. I

    Is Static Friction Capable of Doing Work?

    I understand the whole explanation about why static friction does no work-- I'm just confused about one of the consequences of that. Consider the picture above. The ring is being pulled down the incline with a force of mg*sin(θ). If you analyze the system about the axis at the center of mass of...
  26. F

    Direction of friction on two stacked boxes

    Homework Statement Solve the free diagram of two stacked boxes on a frictionless table accelerated by a force. Homework Equations [/B] None The Attempt at a Solution I have box 2 stacked on box 1. Box 1 is on a frictionless table and accelerated by a force. However, there is friction...
  27. starstruck_

    How do you know which way friction points?

    I was working on a centripetal question where it said that on glare ice, any car needs to travel 60 km/h to successfully make it through the banked highway, and in good road conditions, a car travels at 90 km/k, I had to calculate the coefficient of static friction. When drawing my FBD, I made...
  28. O

    Pulling an object at an angle with friction -- find the Kinetic Energy

    Homework Statement A boy pulls a sled (mass m=59.2 kg) along the ground using a force of magnitude F = 586 N inclined at an angle of θ=37.3° to the horizontal. There is friction between the sled and the ground with a coefficient of µk = 0.205. If the sled starts at rest, how much kinetic energy...
  29. J

    Applied force compared friction force at constant velocity

    Homework Statement How does an applied force and a frictional force compare when moving at constant velocity? Homework EquationsThe Attempt at a Solution
  30. H

    How does the reaction force of friction affect the ground?

    Suppose I am trying to push a heavy block on ground and I haven't applied a force stronger than the maximum static friction. The force of friction acts on the block and its equal and opposite force acts on the ground. Does the reaction force of friction(acting horizontally on the ground)...
  31. B

    How do I find the the coefficient for kinetic friction given

    A 10.0 kg box rest on a horizontal board. One end of the board is slowly raised to 12.8° with the floor, the box slides at a constant velocity. (Use this information to find the kinetic coefficient). Find the magnitude and direction of the acceleration of the box when the board is raised to an...
  32. Alexanddros81

    Banked Curve-Determine smallest static coefficient of friction

    Homework Statement 13.49 The flatbed railway car travels at the constant speed of 80 km/h around a curve of radius 55m and the bank angle 15deg. Determine the smallest static coefficient of friction between the crate and the car that would prevent the crate of mass M from sliding. Homework...
  33. O

    What is the total amount of work done by friction?

    Homework Statement Consider a rope of mass M and length L, resting on a horizontal table, as shown in the figure. The coefficient of kinetic friction between the table and the rope is μk. Let's consider the work that's done by friction as we slide the rope off the table. a.) Consider a small...
  34. S

    Friction between sled and rider

    Homework Statement Ginny has a plan. She is going to ride her sled while her dog Foo pulls her, and she holds on to his leash. However, Ginny hasn’t taken physics, so there may be a problem: she may slide right off the sled when Foo starts pulling. The sled has mass m, and Ginny has mass M...
  35. E

    Is Counter-Steering the Only Way to Change Direction on a Motorcycle?

    On a frictionless road and tires, I know the rider wouldn't be able to change the combined center of gravity of the system by moving his weight around. If he pushes the bike to lean to the right, he would go to the left by the amount that would keep the combined cog the same. But a bike with...
  36. B

    Help with finding Normal Force of inclined plane

    So this is the problem: A 250-kg crate is on a rough ramp, inclined at 30° above the horizontal. The coefficient of kinetic friction between the crate and ramp is 0.22. A horizontal force of 5000 N is applied to the crate, pushing it up the ramp. What is the acceleration of the crate? Relevant...
  37. K

    Calculating Kinetic Friction Coefficient for Sliding Soccer Player

    [note from mentor: this was originally posted in a non-homework forum, so it lacks the homework template.] Hi guys, I need your help with the last part of following problem please. A soccer player with 70kg mass slides for 0.75 seconds on the grass to stop a soccer ball. 1) Acceleration...
  38. A

    Calculating Distance for a Train on a 1% Grade

    Can anyone help with the following question, please? 1. A 60,000kg train is being pulled up a 1 percent grade (it rises 1m for each horizontal 100m). The friction force opposing the motion of the train is 4,000N. Initial speed of the train is 12 m/s. Through what horizontal distance will the...
  39. E

    Me, A Rod and A Table With Little Friction

    Lets say I have a massive rod laying on a table with little froction, screwed into the table on one side to become our pivot point, and I lay next to it with my feet pointing towards the rod. First scenario: I position myself very close to the pivot point and push, the rod rotates and I move...
  40. F

    Friction at the axle vs at the Tyre

    Typically how do the two frictions, namely 1. at the axle of a car wheel vs 2. friction experienced by tyre at the road surface compare with each other? are they some what equal ?.. I am interested in approximate ratio of the two values . Thx.
  41. J

    Static Friction carnival ride Problem

    Homework Statement In a classic carnival ride, patrons stand against the wall in a cylindrically shaped room. Once the room gets spinning fast enough, the floor drops from the bottom of the room! Friction between the walls of the room and the people on the ride make them the “stick” to the wall...
  42. NoahCygnus

    Does work energy theorem fail while dealing with friction?

    Let's consider a setup consisting of a table with friction, and a block on top of it. Suppose we drag the block across the table with a constant speed. The applied force ##f_{app}## acting through a distance ##d## does a work ##f_{app}d##. The frictional force ##\mu N## is equal to ##f_{app}##...
  43. A

    Friction Force with Incline and Pulley

    Homework Statement There is a mass m1 on an incline (angle α), connected to a pulley with a string, and on the other side of the pulley, after another string, there is a mass m2. See picture if it's unclear, I'm not sure how to express the problem. Anyway the plane has a friction coefficient...
  44. D

    Coefficient of friction between stick and circle

    Homework Statement Using the results from problem 2.18 for the setup shown in the Figure below show that if the system is to remain at rest, then the coefficient of friction:a) between the stick and the ground must satisfy $$ μ ≥ \frac {sin(Θ)cos(Θ)} {(1+cos(Θ))(2-cos(Θ))} $$ Homework...
  45. S

    A box over an inclined plane with a mass, no friction

    Homework Statement We have an inclined plane with a mass ##M## and an angle ##\alpha## and a box of mass ##m## over it. Everything is at the instant 0 (it's a problem of static, no dynamics). a) What's the acceleration in the component x of the box? b) What's the acceleration in the component y...
  46. Nikhil Rajagopalan

    Is the Work Done by Static Friction Always Zero in a Round Trip?

    Friction is said to be a non conservative force. And I see various sources state that work done by a non conservative force on a round trip is always non zero. But is that always true? In a case where a coin is placed on a turn table, and the table is rotated, and the coin does not move during...
  47. T

    Find friction coefficient given initial and final velocity

    I am not sure how to approach a problem involving the friction coefficient when only given initial velocity, final velocity, and distance traveled. I could combine the friction and kinematic equations, but I am only familiar with doing that for one velocity... Here is the specific problem I had...
  48. B

    Very difficult mechanics problem with friction

    Homework Statement A hollow cylinder with mass m and radius R stands on a horizontal surface with its smooth flat end in contact the surface everywhere. A thread has been wound around it and its free end is pulled with velocity v in parallel to the thread. Find the speed of the cylinder...
  49. T

    Questions about friction losses in an electric motor

    1) What is friction loss / are friction losses? 2) How can it be determined / measured / calculated / figured out? 3) How does it affect the power output (force * speed) of an electric motor when an electric motor is moving / lifting objects? Why does it have such affects?
  50. J

    Draw a FBD, calculate tension in the string, determine mass

    Homework Statement A box slides on a smooth (frictionless) horizontal surface, 1.50 m above the floor, at a speed of 2.00 m/s. The box then slides down a ramp that makes an angle of 36 deg with the horizontal and has a coefficient of kinetic friction equal to 0.430. After reaching the end of...
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